Foam-forming apparatus



'F. L. BOYD ETAL FOAM-FORMING APPARATUS JuneZO, 1950 .1 & YR m P w w. R a mm Em A NE Y June 20, 1950 F. BOYD ETAL Fom i'oaumc APPARATUS Filed Feb. 23, 1946 INVENTORY Fmnz'qa L. BOYD LEwis W-BOERNE .R

Patented June 20, 195

FOAM-FORMING APPARATUS Fisher L. .Boyd, West Chester, and Lewis W. Boerner, Newtown Square, Pa., assignors to National Foam System, Inc., Philadelphia, Pa., a corporation of Delaware Application February 23, 1946, Serial No. 649,698

2 Claims. (Cl. 261-116) This'invention relates generally to apparatus for use in the production of mechanical or air foam employed in the extinguishment of fires and more particularly to improved means for insuring entrainment of such sufficient amount of air in a flowing stream of water containing a foamforming agent as to produce a stable, durable and large volume of foam satisfactory for fireextinguishing purposes.

Among the principal objects of the present invention is the provision of a simple and inexpensive and yet exceedingly eiiicient design and construction of nozzle which is operative to effect the discharge at high velocity of a stream of foam-forming solution generally in the form of an outwardly flaring cone, the pattern of the discharge stream in the air-entraining zone being such that it not only insures maximum entrainment of air in the stream, but also insures more intimate mixing of the air and solution through out the cross-sectional area of the stream to thereby increase the volume of foam produced.

More particularly, it is an object of the present invention to provide a high velocity discharge nozzle for a stream of foam-forming solution of such design and construction as to finely subdivide and disperse the stream at the locus of introduction of the air, said discharge nozzle operating to create turbulence and dispersion of the stream by causing the latter to discharge generally in the shape of an outwardly flaring hollow cone having internal segments of solid form which extend radially inwardly ofthe external surface of the conical stream and issue from the nozzle in paths paralleling the nozzle axis, the effect of such internal segments being not only to increase the surface area of the stream by fluting the external surface thereof, but also to draw the entrained air toward the center of the stream for more effective distribution thereof throughout the cross-sectional area of the stream.

Still another object of the present invention is to provide a simple and effective means for supporting the stream fiuting member in operative position within the nozzle bore, as well as to provide improved means for drawing a foamforming liquid into a flowing stream of water by the suction action induced by the latter as it passes through the bore of the nozzle.

A still further object is to provide an effective hand-hold for the nozzle which is so designed that it shields the latter from injury and bridges the air-gap between the nozzle and its associated foam discharge tube without in any way interfering with the free entrainment of 2 air in the stream of foam-forming solution issuing from the discharge outlet of the nozzle.

Other objects and advantages of the invention will be apparent more fully hereinafter, it being understood that the present invention consists substantially in the combination, construction,

location and relative arrangement of parts, all as will appear more fully hereinafter, as shown in the accompanying drawings, and'as finally pointed out in the appended claims.

In the accompanying drawings, which are illustrative of a preferred embodiment of the present invention:

Figure 1 is a view showing the nozzle unit of the present invention in association with a foam discharge tube and a pick-up tube for the foamforming liquid which is drawn into the water stream as it passes through the nozzle:

Figure 2 is a longitudinal sectional view of the nozzle unit;

Figure 3 is a transverse sectional view taken on the line 3-3 of Figure 2;

Figure 4 is a transverse on the line 44 of Figure 2;

Figure 5 is a longitudinal sectional view taken on the line 5-5 of Figure 2;

Figure 6 is a transverse sectional view taken on the line 6-6 of Figure 2;

Figure 7 is an enlarged end elevational view of the conical element fitted in the discharge end of the nozzle; showing the general pattern of the stream as it discharges from the nozzle; and

Figure 8 is an exploded view showing in section the several component elements of the nozzle unit.

Referring now to the drawings and more particularly to Figures 1 and 2 wherein the nozzle unit of the present invention is designated generally by the reference numeral l0, it will be observed that said nozzle is adapted to be consectional view taken 'nected by means of its interiorly threaded end I l to a conduit (not shown) through which water under suitable pressure is supplied to the nozzle for mixture with a suitable foam-forming material and air to form foam in accordance with principles well known and understood in the art, the foam so produced being discharged by way of a foam discharge tube I2 for application to the fire to be extinguished.

While in the form of the apparatus illustrated in the drawings, the foam-forming material, de-

rived from a suitable source of supply by way of a a the water passing therethrough, it will be understood, of course, that the nozzle of the present invention is equally adapted for use in connection with so-called pre-mixed foam forming solutions, in which case the foam-forming material is preliminarily introduced into the water stream at a point removed from the nozzle to form a suitable foam-forming solution which is delivered to the nozzle under sufllcient pressure to eflect its discharge therefrom in the form a high velocity stream or let.

Referring now more particularly to Figures 2 to 8, inclusive, it will be noted that the nozzle l essentially consists of a main body member it, having a central bore i5 extending longitudinally therethrough, said bore consisting of a rear section i5 which is in communication with a forward section II of enlarged diameter. The rear end of the body member I5 is internally provided with an enlarged entrance l5 leading into the rear section l5 of the central bore, said rear section it being of such restricted diameter in relation to the diameter of the forward section II as to form an ejector for drawing foam-form- ,ing material into the water stream by the suction induced by the latter as it emerges from the passage l6 and passes through the enlarged passage H. The rear end of the body member I4 is externally fitted with a freely revoluble coupling member is by means of which the nozzle is readily connected to the conduit (not shown) leading to the source of water or foam-forming solution which is delivered thereby under suitable pressure to the nozzle for discharge therefrom by way of the bore I5.

Fitted within this bore I5 is an axially extending stem 20, the rear end of which is suitably supported in fixed position centrally within the enlarged entrance I! to the bore. Preferably, the rear end of the stem 20 is projected through a supporting bar 2|, which extends transversely of the entrance l5 and is secured in position, as shown, by a pair of screws 22-22, the stem bein provided with an annular shoulder element 23, which abuts the inner face of the supporting bar while the rear extremity of the stem 20 is spun over or upset, as at 25, against the outer face of the bar. The stem and its supporting bar thus constitute a flxed assembly which is adapted for insertion into or removal from the body member M as a unit.

The forward end of the stem 20 is provided with an integral deflector element 25 generally in the form of a truncated cone, the base 25 of which is disposed substantially in the transverse vertical plane of the terminal end of the bore l5. This terminal end of the bore is, of course, the terminal end of the enlarged passage l1, and it will be noted that said terminal end is outwardly tapered, as at 21, in correspondence with the taper of the deflector element 25 to provide an outwardly flarin restricted annular discharge passage 28 for the liquid stream passing through the nozzle.

As most clearly appears in Figures 2, 4 and '7, the frusto-conical element 25 is provided with a plurality of circumferentially spaced indentations 25, each extending the full length of the element 25. These indentations are each generally of V-shape in transverse cross-section with the taper or spread of the V increasing from the truncated end 30 of the conical element outwardly toward the base end 23 thereof. In addition, these indentations 29 are characterized by the fact that the ridge lines 3| thereof are disposed in parallel relation and extend as straight-line contlnuations of the circular surface of the main body of the stem 25. Preferably, the deflector element 25 is provided with four of such V-shaped grooves or indentations, although, if desired, a greater or lesser number thereof may be provided, their function being to provide fluted passages for the liquid stream, which are supplemental to the outwardly flaring annular discharge passage 25 formed between the conical surface of the deflector element 25 and the tapered internal surface 21 formed at the terminal end of the passage II.

The liquid discharged from the nozzle is generally in the form of an outwardly divergent annular stream of such ample external surface as to render it capable of entraining a substantial quantity of air from atmosphere in the region immediately in advance of the nozzle, the divergent character of the discharged stream being imparted thereto by the flared shape of the frusto-conical deflector element 25. The fluted passages 25 formed in this element permit circumferentially spaced portions of the stream to discharge rectilinearly from the nozzle in the form of auxiliary solid high velocity jets which are internal'of and contiguous to the annular outer body of the stream. These auxiliary jets spread in width as they leave the nozzle due to the gradually increasing width of the fluted passages from which they emerge, with the result that they eventually commingle in the space immediately within the outer boundary of the annular stream to ,render the stream internally turbulent. At the same time, these auxiliary internal jets, due to the fact that they traverse rectilinear paths paralleling the central axis of the stream, tend to draw the outer annular body of the stream inwardly toward said axis and so provide the stream with a scalloped or clover-leaf outline of the shape shown generally .in Figure 7, thus increasing very materially the external surface area of the stream.

As has already been mentioned, the liquid stream passing through the bore i5 of the nozzle at high velocity indicates a suction action in the region where it emerges from the restricted section I 5 of the bore, this suction action being utilized to draw into the water stream a suitable foam-forming agent by way of pick-up tube l3. In order to most efliciently introduce the foam forming agent into the water stream, the nozzle body It is provided with a pair of passages 32-32 respectively extending laterally and substantially tangentially of the enlarged diameter passage I! (see particularly Figure 6). The outer ends of these lateral passages 32-32 commonly communicate with an internally threaded opening 33 formed in the side wall of the nozzle body for receiving one end of the pick-up tube [3 (see Figures 1 and 2) leading to the source of foam-forming material, the sidewall of the nozzle body being suitably thickened in the region of the opening 33 to accommodate the later.

It will be apparent that when the nozzle is connected to the water suppl line (not shown), water under suitable pressure enters the bore l5 and in passing from the section l6 thereof into the enlarged section II, induces an injector action which causes the foam-forming material to be drawn by suction from its source of supply into the water stream by way of the pick-up tube i3 and the passages 32-32 leading into the passage l'l. Inasmuch as these passages are substantially tangential to diametrically opposed sides of the high velocity stream entering the passage l1, the foam-forming material is quickly brought into contact with the entire surface of the water stream as it passes through the nozzle, thereby insuring rapid introduction and complete dispersion of the foam-forming material into and through the water stream. A foam-forming solution is thus formed within the nozzle from which it is discharged for subsequent entrainment of air to produce foam of a volume and consistency suitable for fire-extinguishing purposes.

As most clearly appears in Figures 2, 4 and 8, the nozzle body 14 is externally provided with a plurality of circumferentially spaced radially extending elements 34, each having a forwardly extending portion 35 providing a seat for the inner end of the foam discharge tube I2, said end of the tube being fitted snugly over and about said seat portions 35 so that it is in axial alinement with the nozzle l0. These tube-supporting elements 34 are respectively provided with radially extending portions 36, the forward edges 31 of which are disposed substantially in the transverse plane of the terminal end of the nozzle, these edges 31 serving as abutments for rear end of the tube.' The latter is preferably provided with radially extending elements 38 through which screws 39 are projected into the edges 31 of the tube-supporting elements to fixedly secure the tube in position. It will be noted that the inner end of the tube I2 is of larger diameter than that of the proximate end of the nozzle l0, thesaid ends of the tube and nozzle being thus maintained in spaced relation to permit the free passage of air from atmosphere into the region of the stream discharged from the nozzle.

The radially extending portions 36 of the tubesupporting elements additionally serve to center about the nozzle an external shield 40, the

rear end of which is snugly fitted about an an-- nular flange 4| integrally formed upon the rear end of the nozzle body. One or more screws 42 secure the rear end of the shield to said flange, it being observed that the forward portion 43 of the shield is of such enlarged diameter and so extends forwardly of the discharge end of the nozzle that it is disposed in spaced relation about the inner end of the foam discharge tube. Thus, air from atmosphere is free to pass in the direction of the arrows shown in Figures 2 and 5 for entrainment with the foam-forming solution discharged from the nozzle into the entrance end of the foam discharge tube.

As has been previously indicated, the nozzle of the present invention is adapted for use in connection with pre-mixed foam-forming solutions, in which case the pick-up tube is dispensed with and the opening 33 in the side wall of the nozzle body is closed with a suitable plug (not shown), the pre-mixed solution being delivered directly to the nozzle for discharge therefrom in the form 6 of a high velocity stream into which air is entrained to produce foam.

It will be understood, of course, that the present invention is susceptible of various changes and modifications which may be made from time to time without departing from the general principles or real spirit thereof, and it is accordingly intended to claim the same broadly, as well as specifically, as indicated in the appended claims.

What is claimed as new and useful is:

1. In an apparatus for producing fire extinguishing foam, a discharger for a foam-forming solution including a main body member having a central bore therethrough terminating in an outwardly flared discharge end, a tapered deflector coaxially and permanently disposed wholly within said flared discharge end to provide an outwardly flaring annular discharge passage between said tapered deflector and the terminal end of said bore, said deflector being provided with a plurality of circumferentially spaced flutes extending lengthwise of said deflector, said flutes being each of gradually increasing width outwardly toward the terminal end of said deflector,-

and an open ended conduit carried by said body member and having an air entrance surrounding the discharge end of said body member.

2. In an apparatus for producing fire extin-.

guishing foam, a discharger for a foam-forming solution including a main body member having a central bore therethrough terminating in an outwardly flared discharge end, a longitudinally extending stem extending through said bore in coaxial relation therewith, the rear end of said stem being fixedly secured to said main body member and the forward end being provided with a frusto-conical deflector member permanently disposed concentrically and wholly within the discharge end of said bore to provide an outwardly flared annular discharge passage for the solution, said deflector member being externally fluted to provide a plurality of fluted passages continuous to and supplementing said annular discharge passage, and an open ended conduit carried by said body member and having an air entrance surrounding the discharge end of said body member.

FISHER L. BOYD. LEWIS W. BOERNER.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,405,810 Wilkie Feb. 7, 1922 1,758,119 Le Moon May 13, 1930 2,031,379 Mathieu Feb. 18, 1936 2,183,284 Wiebicke Dec. 12, 1939 2,183,561 Hamblin Dec. 19, 1939 2,388,508 Timpson Nov. 6, 1945 

